Pity that's not XML, though.
It was in XML1.0 and is still widely used. I agree that XML Schema is the current way, but it is very
, although more flexible and powerful. It can be used for the same things, though.
There goes scriptability and so many of the lovely Unix administration tools we've grown to love over the past few decades.
I'm not sure why. If we want the validation of, say, a DTD, then we need a (possibly) new tool for that. What validates crontab, for example? When I build a major app, I often build validation tools for the config files. I find it easier to use XML and a DTD than going through the difficulty of writing my own parsing and validating code.
Yes, I do understand and agree that the application needs to validate all input. I just like the idea of an external tool to do the first pass.